Mandy Bannon sent this message by email:
Mike took this photograph of a writhing bundle of big orange caterpillars – yesterday ( July 11th) on Pony Wood – Aldcliffe Rd path. It was about 5 yards down from the bend where the bench is (on Flora field side of the path). If you zoom in, you’ll see above the caterpillar masse is a fine cobwebby structure that they appeared to be leaving.
Do you know what they might be?